The Guiana Highlands are located in northern South America, extending from South Venezuela through Guiana and southward into Brazil. The range is comprised of several huge and isolated mesas, their sheer walls towering above the Amazon forests. Sculpted by weather, these great cliffs present an extraordinary landscape of towering pinnacles and monoliths. Because of their ancient isolation from the forest floor, an entirely unique ecosystem has evolved on the mesa tops, including unique species of plants, insects, and animals. The highest of the Guiana Highlands is Mount Roraima (9,094 ft.). The world's highest waterfalls are also found here, including several that plunge over cliffs 1,000 feet high. Angel Falls is the highest, with a 3,212 foot drop.